molecules.cpp:1:9: warning: #pragma once in main file
1 | #pragma once
| ^~~~
molecules.cpp: In function 'std::vector<int> find_subset(int, int, std::vector<int>)':
molecules.cpp:9:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
9 | for (int i = 0; i < w.size();++i)
| ~~^~~~~~~~~~
molecules.cpp:34:31: error: 'struct std::_Rb_tree_const_iterator<std::pair<int, int> >' has no member named 'second'
34 | v.push_back(b.second);
| ^~~~~~